1. Field of the Invention
The present invention relates to methods for controlling maintenance of printing apparatuses and information processing apparatuses. Specifically, the present invention relates to a method and apparatus for controlling execution of maintenance for a printing apparatus such as a registration adjustment which adjusts a deviation of print position in the printing apparatus.
2. Description of Related Art
A registration adjustment is known as a typical maintenance in printing apparatuses such as ink jet printers. With what is called a serial type of an ink jet printer that executes printing by scanning a print head over print media such as sheets, when printing involves both forward and backward scans of the print head, ink landing position may deviate between the forward scan and the backward scan. To prevent this, the registration adjustment is executed by detecting the deviation and on the basis of the detection, adjusting ejection timings of the print head and the like.
FIGS. 1A to 1C are diagrams illustrating a registration adjustment. FIG. 1C shows an entire test pattern used for the registration adjustment. The (data on) test pattern is divided into pieces. A forward scan is executed to print a pattern having print areas located at fixed intervals in a scanning direction as shown in FIG. 1A. Further, a backward scan is executed to print a pattern complementary to the forward pattern in the same scan area as that for the forward scan, as shown in FIG. 1B. Then, the ejection timing for at least one of the forward and backward scans is changed. The resulting timings are used to print the same forward and backward patterns in a different area. This results in patterns corresponding to the respective changed timings, such as patterns A to E in FIG. 2. Then, a user selects one of these patterns which is most similar to the pattern shown in FIG. 1C and inputs information on the selected pattern. In the example shown in FIG. 2, the pattern C is selected. Selection of the pattern C, that is, selection and inputting of the ejection timing for this pattern, sets a registration adjustment value that minimizes the deviation of landing positions of ink droplets in bidirectional printing. It should be noted that for each of a plurality of nozzles in the print head, the registration adjustment may also be executed.
The registration adjustment as described above is desirably executed on all the nozzles of all the ink colors for the print head that are used in the ink jet printer. However, recent printers use a very large number of nozzles and ink colors, and therefore registration adjustment requires a very long time in the case that the adjustment is executed for all nozzles and ink colors. Further, certain ink colors provide insufficient visibility, making the adjustment difficult. Thus, the desirable mode of a registration adjustment is such that a detailed registration adjustment such as a registration adjustment of all the nozzles for all the ink colors is only executed as required.
On the other hand, the deviation of ink landing position of the print head may occur during a manufacture process for an unavoidable reason involving the differences among individual print heads or while the print head is in use, owing to a change in ejection condition (aged variation). For the deviation occurring during manufacture, individual differences among production lines are still occurring, but the differences among the nozzles in the same print head are relatively small because of improved manufacturing accuracy. Consequently, the user's first operation of a printer following purchase does not require a detailed registration adjustment which executes a registration adjustment on all the nozzles for all the ink colors. In this case, a simplified registration adjustment is sufficient which executes a registration adjustment only on some of the ink colors and some of the nozzles. Then, the detailed registration adjustment is executed when the ejection condition seems to have changed after a number of operations of the printer.
In these circumstances about the registration adjustment, in conventional registration adjustment control modes, the user is provided with a configuration for instructing the execution of a registration adjustment without distinction between the simplified and detailed versions so that upon receiving this simple adjustment instruction, the printer determines whether or not this is the first time to execute a registration adjustment and correspondingly determines which registration adjustment is to be executed. Specifically, upon receiving the user's registration adjustment instruction via a host computer such as a personal computer (PC), the printer reads the ID of the mounted print head or data from a memory in the printer. The printer thus determines whether or not the print head has been subjected to a registration adjustment before to correspondingly determine whether the simplified registration adjustment or the detailed registration adjustment is to be executed.
As similar method that executes certain adjustment or processing on the basis of the printer's own determinations, a method is known which determines execution timings for a print head ejection recovery process to be executed, on the basis of the accumulated number of ink droplets ejected and the analysis of print data to be printed (Japanese Patent Application Laid-Open No. 2003-118145). This enables timings for an ejection recovery process to be automatically set depending on a print amount or the like.
However, the registration adjustment involves operations which require inputting of the required type and number of sheets, how to use adjustment patterns, and adjustment values, and is complicated compared to other adjustments or processes. Thus, in many cases, a user interface in the host computer such as the PC desirably shows a user what operations the user should perform for the registration adjustment. For example, in response to an instruction from the user instructing the execution of a registration adjustment, the host computer provides guidance for preparation for the registration adjustment, for how to check the patterns, and for inputting of adjustment values. The guidance is provided by software such as a printer driver or maintenance utility.
To allow the host computer to provide proper guidance, it is desirable that the host computer previously determines whether the required registration adjustment for the printer is of the detailed version or the simplified version. As a configuration achieving this, some printers return, upon receiving the instruction to execute the registration adjustment, an informative status indicating which of the simplified and detailed registration adjustments the printer is to execute. The printer driver or maintenance utility then presents appropriate guidance or a setting value input screen in accordance with the returned status.
However, when the printer is powered off or temporarily remains busy, the host computer cannot obtain the printer status when it is needed. Further, for example, the Microsoft's operating system Windows (registered trade mark) makes it possible to set the function of bidirectional communication between the PC and the printer to be disabled. Thus, if the function is turned off by the user for any reason, the host computer cannot acquire the printer status. Unfortunately, in this case, the appropriate guidance for the registration adjustment cannot be presented.